Introduction: Effects of melatonin (MT) were comparatively examined on melanophores of isolated skin in adults and tadpole’s tailfin of a frog Rana cyanophlyctis. MT is generally considered as a potent melanophores aggregating hormone besides regulating the sleep wake cycle in vertebrates. Methods: Melanophore size index (MSI) was chosen as a recording parameter of the responses. Concentr...

We describe the tadpole of Sphaenorhynchus caramaschii. It differs from tadpoles of other species of Sphaenorhynchus in having a short spiracle, submarginal papillae, and alternating short and large marginal papillae in the oral disc. Some larval characteristics, like morphology and position of the nostrils, length of the spiracle, and size of the marginal papillae on the oral disc are discusse...

One prediction of optimal digestion theory is that organisms will increase the relative length of their digestive tracts when food resources become limited. We used theory of optimal digestion to test whether tadpoles can adjust the relative length of their intestines when challenged with the fungal pathogen Batrachochytrium dendrobatidis (Bd). The degree of tadpole mouthpart damage, a symptom ...

Premetamorphic tadpoles of Xenopus laevis reared in water containing 001 % propylthiouracil are developmentally retarded and metamorphosis is prevented. When uncrowded, they continue to grow to a giant size. Moderate crowding leads to a slower rate of growth. Thus morphologically premetamorphic tadpoles were produced with lens diameters appropriate to either normal premetamorphic, climactic or ...

Inclusive ¢tness theory predicts that altruism should often be directed towards reproductive relatives, but it is unclear whether individuals that are most likely to help or harm relatives are also most likely to identify kin in the ¢rst place. Here I show that species and sibships of spadefoot toad tadpoles (Spea bombifrons and S. multiplicata) that were most likely to produce an environmental...

From the 24 species allocated in the genus Hylodes, 16 have their tadpoles described, which five have information on the oral anatomy. Herein, the internal oral morphology of the tadpoles of H. dactylocinus, H. heyeri, H. aff. lateristrigatus, H. magalhaesi, H. meridionalis, H. phyllodes, H. sazimai, and H. uai is described, along with comparisons among all species in the genus with previously ...

Premetamorphic tadpoles of Xenopus laevis reared in water containing 0.01% propylthiouracil are developmentally retarded and metamorphosis is prevented. When uncrowded, they continue to grow to a giant size. Moderate crowding leads to a slower rate of growth. Thus morphologically premetamorphic tadpoles were produced with lens diameters appropriate to either normal premetamorphic, climactic or ...

If invasive species use chemical weapons to suppress the viability of conspecifics, we may be able to exploit those species-specific chemical cues for selective control of the invader. Cane toads (Rhinella marina) are spreading through tropical Australia, with negative effects on native species. The tadpoles of cane toads eliminate intraspecific competitors by locating and consuming newly laid ...

A mutant gene, Pale, (/=") has been discovered in the discoglossid frog, Bombina orientalis. Breeding experiments indicate that the gene is recessive to the wild-type allele (P). Embryos, tadpoles and adults homozygous for the Pale gene are lighter in coloration than wild-type animals. Eggs produced by Pale females appear normally pigmented. Neural-retina defects were apparent in Pale tadpoles....

Metamorphosis of anuran tadpoles is controlled by thyroid hormone (TH). Here we demonstrate that transgenic Xenopus laevis tadpoles expressing a dominant negative form of TH receptor-alpha are resistant to a wide variety of the metamorphic changes induced by TH. This result confirms that TH receptors mediate both early and late developmental programs of metamorphosis as diverse as growth in the...